Trying to install postgres on mac osx but after ruing initdb there was no config file for postgres

This is my first time on these forums so if I do something wrong please correct me,

So I am following this tutorial on how to install metasploit: http://hackerforhire.com.au/installing-metasploit-framework-on-os-x-el-capitan/

but after doing initdb on postgresql, typing postgres into terminal complains that it can not find any config files.